1. Field of the Invention
This invention involves a hypocholesterolemic composition for oral administration comprising an association of soya proteins with sitosterols. The soya proteins and the sitosterols may be of natural origin.
The types of vascular damage that can be caused by a hypocholesterolemic condition are numerous; and a balanced diet plays a role of primary importance in the prevention of such alternations. The populations that are more exposed to this type of pathology are the richer ones whose normal everyday diet, apart from being unbalanced, often exceeds daily requirements.
Hypercholesterolemia can be treated either pharmacologically or by undertaking preventative action in terms of modifying or integrating the usual nutritional intake.
The influence of soya proteins on nutrition is observable both in normal cholesterol level and in hypocholesterolemic conditions.
Sitosterols, β-sitosterols in particular, are substances that are used extensively in hypocholesterolemic treatments. Their chemical structure, similar to cholesterol, differs because of an ethyl group bound to the carbon in position 24, provides these substances with an absorption behavior which is very different from that of cholesterol.
These substances, contrary to the cholesterol contained in food, are not absorbed and interfere with the absorption of the cholesterol taken in. The limited food absorption causes a consequent and significant hypocholesterolemic effect.
2. Description of Related Art
GB-A 2 028 341 describes the use of a composition containing soya protein and pectin for reducing cholesterol level. The daily dose is 60–90 g/day soya protein and 1.5–3 g/day pectin.
GB-A 1 427 253 discloses an antilipemic composition comprising a nonsaponifiable fraction of soybean oil, said fraction containing about 45% by weight of plant sterols (campesterol, stigmasterol, and β-sitosterol) and about 20% by weight tocopherols. The use of this fraction allows the user to reduce dramatically the daily dose of sitosterol compared to the prior art. It is shown that 1200–1800 mg/day of this composition significantly lowers the cholesterol level in patients.
In GB-A 1 427 253 the problem is solved or ameliorated by the use of a nonsaponifiable fraction of soybean oil. Although the hypocholesterolemic effect of soya protein is disclosed in GB-A 2 028 341, there is nothing in either GB-A 2 028 341 or in GB-A 1 427 253 that would suggest that soya protein and sitosterols could have a synergistic effect that would lead to a significant decrease in t he daily dose of both compounds.
EP-B 669 835 describes hypocholesterolemic compositions with soya proteins associated synergistically with sitosterol. These compositions contain from 50 mg to 2000 mg of Soya proteins and from 10 mg to 1000 mg of sitosterols per unit, both of natural origin.